police say adam lanza drove to sandy hook elementary school arriving around 9:30. unable to gain entry through the main entry, he broke through a window, and that's when police say his shooting rampage began. in total 20 children were killed as well as 6 adults. there were also two surviving adult victims. police say adam lanza turned a gun on himself when he heard and first saw the responders coming onto the scene. three guns were recovered from inside the school. there they are. one handgun was left in lanza's car. we're joined by nbc national investigative correspondent michael isikoff in newtown, connecticut. michael, thanks so much for joining us. we've only got about three minutes for your presentation, so run through what you think is salient, what you have been able to put together about the motive and the method of this killer. >> well, first of all, chris, about motive, we are still clueless. he didn't have any connection to the school at all. he may have gone there as a child. in fact, he probably did according to friends, but he didn't work there, he ha